An occupancy sensor is disclosed including a passive infrared (PIR) sensing element, a temperature sensing element, and a processor. The processor receives temperature signals from the temperature sensing element and configures the occupancy sensor into a selected operating mode based the received temperature signal. The operating mode may be associated with a predetermined sensing threshold of the PIR sensing element. The processor controls an associated load based on the selected operating mode and the received occupancy signals. The occupancy sensor can alternatively include an occupancy sensing element and a photodetector. Based on the amount of light detected by the photodetector over time, the occupancy sensor can calculate a rough estimate of time of day, and can automatically adjust one or more sensing and/or operational characteristics based on that time of day determination. A photosensor may implement daylight harvesting based on different light levels associated with different times of day.